Answer to Question 1
The inevitability comes because in growing populations, the numbers of young
females is proportionally greater than in stable populations. A young-weighted population
will produce more children than one with the same proportion of people at each age range.
Thus, population increase is assured by the age structure of the population.
Easterbrook does recognize that events from Nature (or human stupidity leading to nuclear
war) can cause a change in the inevitability of the growth, unlike Simon and like Asimov,
Bartlett, and Kendall (see Questions 2-13, 2-21, and 2-22 above).
Answer to Question 2
A year has 8760 hours (that's why it is the last number on the time axis).
a. If the nuclear plant was online for 70 of 8760 hours, it was available 6132 hours. The
oil-burning plant was available 90 of the time, 7884 hours. The gas turbine was online
1314 hours. Reading from the graph, the nuclear plant cost about 40.40/kW, the oil
burning plant about 33/kW, and the gas turbine, about 25/kW.
The nuclear plant cost 1000 MW x 40.40/kW = 40.4 million to generate 6,132,000
MWh of electricity; the oil-fired plant cost 940 MW x 33/kW = 31.0 million to
generate 7,410,960 MWh, and the gas turbine cost 200 MW x 25/kW = 5.0 million to
generate 282,800 MWh.
b. The total cost is 40.4 million + 31.0 million + 5.0 million = 76.4 million. The total
electricity generated is 6,132,000 MWh + 7,410,960 MWh + 282,800 MWh = 13,805,760
MWh. The cost of generating the electricity was then 76.4 million/13,805,760 MWh =
76.4/13,805,760 Wh = 76.4/13,806 kWh = 0.0055/kWh. Anything over this amount
makes a profit. At the normal cost, the utility has a profit of over 0.07/kWh.